Practice question
Question
A 800kg satellite orbits Earth at 12RE from the center. What is its total energy? (ME\=6×1024kg,RE\=6.4×106m,G\=6.67×10−11N m2/kg2)
Explanation
E = −GMEm2r. r = 12RE = 7.68×107m. E = −6.67×10−11×6×1024×8002×7.68×107. E = −3.202×10171.536×108≈−2.08×109J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to -2.1 × 10⁹ J. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.